chore(github): run e2e workflow against master periodically (#2528)

Run the e2e GitHub workflow against master periodically, twice per day,
at 00:30 and 12:30 ET.

Signed-off-by: Nick Hale <[email protected]>

Author: njhale

.github/workflows/e2e-tests.yml

@@ -1,5 +1,7 @@
 name: e2e
 on:
+  schedule:
+    - cron: '30 5,17 * * *' # run this every day at 5:30 and 17:30 UTC (00:30 and 12:30 ET)
   push:
     branches:
       - master